How to run my NetBeans project?

[David Herron]

To understand the full picture, here is my assignment:

Write an inheritance hierarchy for class Quadrilateral, Trapezoid, Parallelogram, Rectangle, and Square. Use Quadrilateral as the super class of the hierarchy. Make the hierarchy as deep I.e., as many levels) as possible. Specify the instance variables and methods for each class. The private data of the Quadrilateral should be the x-y coordinate pairs for the four end-points of the Quadrilateral. Write a program that instantiate objects of you classes and outputs each object area (except Quadrilateral)

When I try to run this I get:
quadrilateral.Quadrilateral class wasn't found in the Quadrilateral project
Select main class:
"No main class found".

My classes are all separate .java files within my Quadrilateral Java application project

I have a hard time understanding how to use NetBeans, but it is what I am required to use.

Thanks

package quadrilateral;

public class Quadrilateral {

Point point1, point2, point3, point4;

public Quadrilateral( double x1, double y1, double x2, double y2,
double x3, double y3, double x4, double y4 )      
{
    
point1 = new Point( x1, y1 );
point2 = new Point( x2, y2 );
point3 = new Point( x3, y3 );
point4 = new Point( x4, y4 );
}
public Point getPoint1()

{
return point1;
}
public Point getPoint2()

{
return point2;
}
public Point getPoint3()

{
return point3;
}
public Point getPoint4()

{
return point4;
}
public String toString()

{
return "Coordinates of Quadrilateral are: \n" + printCoordinates();
}
public String printCoordinates()

{
return point1.toString() + ", " + point2.toString() + ", " +
point3.toString() + ", " + point4.toString();
}
} // end class Quadrilateral

package quadrilateral;

public class Point
{
        
private double x, y;

public Point( double xCoordinate, double yCoordinate )

{
x = xCoordinate;
y = yCoordinate;
}
public double getX()

{
return x;
}

public double getY()

{
return y;
}
public String toString()

{
return "( " + getX() + ", " + getY() + " )";
}
} // end class Point

package quadrilateral;

public class Trapazoid extends Quadrilateral
{
double height;

public Trapazoid( double x1, double y1, double x2, double y2, double x3, 
        double y3, double x4, double y4 )

{
super( x1, y1, x2, y2, x3, y3, x4, y4 );
}
public double getHeight()

{
if ( getPoint1().getY() == getPoint2().getY() )
return Math.abs( getPoint2().getY() - getPoint3().getY() );
else
return Math.abs( getPoint1().getY() - getPoint2().getY() );
}

public double getArea()

{
return getSumOfTwoSides() * getHeight() / 2.0;
}
public double getSumOfTwoSides()

{
if ( getPoint1().getY() == getPoint2().getY() )
return Math.abs( getPoint1().getX() - getPoint2().getX() ) +
Math.abs( getPoint3().getX() - getPoint4().getX() );
else
return Math.abs( getPoint2().getX() - getPoint3().getX() ) +
Math.abs( getPoint4().getX() - getPoint1().getX() );
}
public String toString()

{
return "\nCoordinates of Trapazoid are: \n" + printCoordinates() +
"\nHeight is: " + getHeight() + "\nArea is: " + getArea();
}

} // end class Trapazoid

[David Herron]

Nevermind.. I did not have a main method for starters.